Thread: what is the domain of this function

can anyone help tell me what the domain of this function is please

f(x) = 1
_________

sqr root of (1-x)(7+x)

Originally Posted by emmalou264

can anyone help tell me what the domain of this function is please

f(x) = 1
_________

sqr root of (1-x)(7+x)

What makes f(x) undefined. ie What make the denominator 0, or what makes the radical undefined (negative)

The domain is all values of x for which the function is defined.

I'll give u one place that it's not defined.........

x<-7

here's another

x>1

here's another

x=1

here's another

x=-7

So are you familiar with interval notation?

Originally Posted by VonNemo19

What makes f(x) undefined. ie What make the denominator 0, or what makes the radical undefined (negative)

The domain is all values of x for which the function is defined.

I'll give u one place that it's not defined.........

x<-7

here's another

x>1

here's another

x=1

here's another

x=-7

So are you familiar with interval notation?

A square bracket means that the endpoint is included. A round bracket means that the endpoint is not included. So a slight correction to this answer is required: (-7, 1).

@OP: Since is required, the interval is most easily found by drawing a graph of the parabola and looking for the values of x such that y > 0.

Originally Posted by mr fantastic

A square bracket means that the endpoint is included. A round bracket means that the endpoint is not included. So a slight correction to this answer is required: (-7, 1).

@OP: Since is required, the interval is most easily found by drawing a graph of the parabola and looking for the values of x such that y > 0.

I simply cannot believe I did that. aaaaaaarrrrrrrrrrrrrrrrrgggggggggghhhhhhhhh!!!!!!! !!!!!!!